Reaction mass of 3-(2-{3-cyanato-5-[2-(3-cyanatoaryl)heteropolycycle-5-yl]aryl}heteropolycycle-5-yl)aryl cyanate and heteropolycycle -2,5-diyldi-3,1-arylene dicyanate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 August 2011 to 18 March 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Details on sampling:

Due to low aqueous solubility of the test substance, it was not possible to develop a suitable method of analysis with sufficient sensitivity to verify concentrations during the study. Therefore, results are reported in terms of the nominal loading rates.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION:
The test medium (100 mg/L) was prepared by weighing the test substance (100 mg) onto a glass cover slip, which was then added to a volumetric flask (1 L) and made up to volume with dilution medium. The contents of the flask were stirred overnight in the dark before the stirrer was turned off and a siphon then inserted at the mid-vessel point. The bulk medium was then left to stand overnight, after which the mid-vessel fraction was siphoned off and used in the test (nominal loading rate of 100 mg/L WAF).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia Magna
- Strain: Straus
- Source: in-house culture originating from a reputable supplier
- Feeding during test: no feed was given during the exposure period
- Method of breeding: Cultures were fed daily with a suspension of the unicellular green algae, Pseudokirchneriella subcapitata, to provide nominally 0.1 to 0.2 mg carbon per daphnid, per day, except during the initial three days when a slightly lower ration was given. Culture conditions ensure that the stock animals reproduce by parthenogenesis. The day before the start of the study, all juvenile Daphnia present were removed from the laboratory cultures. The following morning, juveniles produced by the gravid (egg-bearing) adult Daphnia were removed from the culture vessels and held in a separate holding vessel; these animals, which were less than 24 hours old, were used in the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

None

Hardness:

252 mg/L as CaCO3

Test temperature:

20.8 - 20.5 °C

pH:

7.83 - 7.97

Dissolved oxygen:

96 - 103 (% Air Saturation Value)

Salinity:

Not applicable to a freshwater study.

Nominal and measured concentrations:

Nominal concentration = 100 mg/L
Measured concentrations were not determined due to the very low water solubility of the test substance.

Details on test conditions:

TEST SYSTEM
- Test vessel: dish
- Type: loosely covered
- Material, size, headspace, fill volume: glass containing 100ml of test medium
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 20ml/daphnia

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deionised, reverse osmosis water.
- Culture medium: Elendt M4 culture medium
- Test medium: Elendt M4 culture medium

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16 hours light : 8 hours dark with periods of subdued lighting at the beginning and end of each light phase

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Daphnia were considered to be immobile if they were unable to swim within approximately 15 seconds following gentle agitation of the test vessel. The numbers of mobile, immobile and floating Daphnia were counted approximately 24 and 48 hours after the start of the study.

TEST CONCENTRATIONS
The range finding study employed nominal loading rates (WAFs) of 1, 10 and 100 mg/L. After 48 hours, all of the Daphnia were mobile at all nominal loading rates. Based on these results, the definitive (limit) test employed a single nominal loading rates of 100 mg/L.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No immobilisation or effects on the Daphnia were noted.
Based on these findings, neither the 48-hour EL50 nor the no-observed-effect loading rate could be identified

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Validity criteria fulfilled:

yes

Remarks:

For the study to be valid the number of floating and/or immobile Daphnia in the control group must not be exceed 10% at the end of the test and the concentrations of dissolved oxygen must be > 3 mg/L at the end of the test.

Conclusions:

LZ1554 was not found to be acutely toxic to Daphnia magna when dispersed in water at a nominal loading rate of 100 mg/L.

Executive summary:

The acute daphnia toxicity was determined in a GLP-compliant study in accordance with OECD no. 202 and EC test method C.2. LZ1554 was not found to be acutely toxic to Daphnia magna when dispersed in water at a nominal loading rate of 100 mg/L.

Description of key information

Invertebrates

LZ1554 was not found to be acutely toxic to Daphnia magna when dispersed in water at a nominal loading rate of 100 mg/L. Hence, the48 hour EL50 and NOELR were determined to be > 100 mg/L nominal.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Remarks:

nominal concentrations

Effect concentration:

> 100 mg/L